1. Field of the Invention
This invention relates to a weld gage which is used to measure weld beads, mainly in several welding work or in the construction work, in particular, of ships, bridges, and steel frames.
2. Background Art
As depicted in FIGS. 3 and 4, a conventional weld gage includes a stainless steel gage board 31 about 3 mm thick having main metric graduations 32 formed longitudinally on a back side of a front face, and angle graduations 33 formed longitudinally, on a back side of a back face. A slide groove 34 is formed in the back face of the gage board 31 so as to extend longitudinally at a transversely central position thereof, and metric graduations are longitudinally provided on a foreside of the slide groove 34. Thus, a slide scale 36 is slidably inserted in the slide groove 34 of the gage board 31, and is held in position by means of a retaining bolt 37 and a retaining nut 38. The bolt 37 is inserted into the gage board 31 from the back side thereof, while the nut 38, which is provided with a locking coil spring, is disposed at the front side of the gage board 31 to engage with the bolt 37. Furthermore, an L-shaped root-opening measuring plate 40 is provided on the front face of the gage board 31. Metric root-opening graduations 39 are provided longitudinally on an elongated distal portion, and the root-opening measuring plate 40 is secured to the left corner of the front face of the gage board 31 so as to be pivotable in the forward and backward direction with its proximal end being anchored by a retaining screw 41 and a locking coil spring.
In welding work, such as welding of a general type, welding for construction, shipbuilding, or bridgework, or welding of steel frames, when measuring a butt weld bead, a fillet weld bead, a throat depth, a diameter of a round bar, a difference in level or a plate thickness, a suitable lateral side of the gage board 31 is first brought into abutment with an object being welded in a horizontal or vertical fashion. Then, the retaining nut 38 associated with the retaining bolt 37 is loosened, and the slide scale 36 is slid in the right or left direction along the slide groove 34 to bring it into contact with the top of the butt weld, the fillet weld, the round bar, the planar plate or the like. The butt weld bead, the fillet weld bead, the throat depth, the diameter of a round bar, the difference in level or the plate thickness can be thus measured by reading the slide graduation 35 indicated by the reference graduation 42 provided on the slide scale 36. Similarly, when measuring a pre-processing groove angle, a suitable lateral end of the gage board 31 is brought into abutment with an object being welded. The retaining nut 38 associated with the retaining bolt 37 is then loosened, and the slide scale 36 is released from the slide groove 34 to be pivoted obliquely to be brought into contact with the inclined surface of the object to be welded. The groove angle can be thus measured by reading the angle graduation 33 indicated by the reference graduation 42 indicates. Furthermore, when measuring various root-openings, the retaining screw 41 is loosened to pivot the root-opening measuring plate 40. Then, the distal portion of the root-opening measuring plate 40 is inserted into the various root-openings of the object to be welded. Thus, by reading the root-opening graduations 39 formed on the front face of the root-opening measuring plate 40, the various root-openings can be measured.
However, when measuring the butt weld bead, the fillet weld bead, the throat depth, the diameter of a round bar, the difference in level or the plate thickness, the retaining nut 38 combined to the retaining bolt 37 must be released to move the slide scale 36 along the slide groove 34 in the right or left direction. Also, when measuring the pre-processing groove angle, the retaining nut 38 combined to the retaining bolt 37 must be loosened to release the slide scale 36 from the slide groove 34 and to pivot it obliquely. Thus, the operation of the slide scale 36 and the root-opening measuring plate 40 is laborious. In addition, the main graduations 32, the angle graduations 33 and the slide graduations 35 on the front or back face of the gage board 31, and the root-opening graduations 39 on the front face of the root-opening measuring plate 40 are graduated only in metric units. Thus, it is impossible to measure in inches. Moreover, the slide groove 34 is formed at the center of the thick stainless steel gage board 31 so as to extend longitudinally, and the slide scale 36 is inserted into the slide groove 34 for sliding movement in a longitudinal direction and held by means of the retaining bolt 37 and the retaining nut 38 with a locking coil spring. In addition, the root-opening measuring plate 40 is supported on the left comer of the front face of the gage board 31 by means of the retaining screw 41 and the coil spring. Therefore, the conventional weld gage is so intricate in structure that it is not suitable for mass production, and becomes expensive.